Serhiy Hayday, chief of Luhansk’s regional military administration, said the school building had been destroyed.
“The explosion took place in the building. Rescuers (are) dismantling the rubble as quickly as possible. The chances of (someone still) alive are very slim. There were 90 people in the school building; 27 survived , 60 people most likely died,” Hayday said.
Photos shared from the scene showed rescue personnel searching the smoldering ruins of the schoolhouse.
Survivors of the bombing described their harrowing experience in interviews with CNN.
“I was knocked down by a plate – bent into a ball,” said a man with a bandage over his nose and forehead, who preferred not to give his name for privacy reasons. “Then another explosion, small rocks fell on us. Darkness.”
He continued: “There was a woman in our room who was screaming all the time. She was being pulled out all the time and screaming. I told her, ‘Don’t scream.’ We heard nothing.”
“They started digging,” he said. “I got out. I was like a drunk man – lost.”
Video from the school shared by Hayday on Telegram shows a building completely destroyed by the attack.
Another survivor, Sergiy, said he was in the basement of the school when the bomb hit and that all three floors of the building collapsed “to the ground”.
“We didn’t understand anything,” Sergiy said. ‘We were inside. Suddenly everything fell down. Darkness. That is it.’
Yevgen, meanwhile, described a desperate escape.
“I was the very first to start climbing out,” he said. “I was raking and throwing rocks. There were wooden planks and planks. Residents who weren’t in the basement helped and used a pipe to rip those planks off.”
The survivors said there were several elderly grandparents among the neighbors they sheltered from.
“Imagine what they bombed,” Sergiy said. “An ordinary village with only pensioners and children.”
Western countries reacted indignantly to the bombings. British Foreign Secretary Liz Truss said on Sunday she was “appalled”, adding: “Deliberately attacking civilians and civilian infrastructure amounts to war crimes. We will ensure that Putin’s regime is held accountable.”
Since Moscow invaded Ukraine, Russian forces have repeatedly attacked fleeing or sheltering civilians.
Amnesty International said on Friday that Russian troops should “be brought to justice for a series of war crimes” committed in the region northwest of Kiev, following an investigation the group conducted in Ukraine.
The investigation, based “on dozens of interviews and extensive examination of material evidence”, has documented “unlawful airstrikes on Borodyanka and extrajudicial killings in other cities and towns, including Bucha, Andriivka, Zdvyzhivka and Vorzel”.
Fighting in Luhansk has been going on for months, especially since Russia refocused its invasion on the eastern Donbas region.
Hayday said on Ukrainian television on Saturday, hours before the school bombing, that the situation was difficult.
“The main efforts of the enemy are to break through in Popasna and towards Severodonetsk and Voievodivka. They have deployed most of their troops and equipment there,” he said.
“That’s where the greatest number of shelling and missiles and air strikes are constant – it’s just a terrible situation. Our guys are holding on, we are waiting for help, for reinforcements,” he said.
This story has been updated with additional information.
CNN’s Martin Goillandeau, Radina Gigova and Devan Cole contributed to this report.